Drain valve construction



g- 1969 RA. LOMOLINO 3,460,561

QRAIN VALVE CONSTRUCTION Filed March 21, 1967 INVENTOR.

Paul A. Lomolino BY #M, W, Via

m w W Attorneys United States Patent 3,460,561 DRAIN VALVE CONSTRUCTION Paul A. Lomolino, 3769 Farm Hill Blvd., Redwood City, Calif. 94061 Filed Mar. 21, 1967, Ser. No. 624,788 Int. Cl. F16k 1/20 US. Cl. 137--247.13 1 Claim ABSTRACT OF THE DISCLOSURE A drain valve in the floor of a refrigerated cargo compartment of a railroad car or other vehicle includes a valve closure member at the bottom of the tube which opens upon receipt of liquid in the tube. The closure member is carried on a lever arm which also carries a counter-weight serving to normally urge the closure member to its closed position. The counter-weight and the mass of the closure member serve to create counteracting moments of inertia which nullify one another upon receipt of vertical movements encountered by virtue of the bouncing of the vehicle.

At the upper end of the tube a fluid trap is formed which serves to limit the frequency of operation of the closure member by requiring a predetermined accumulation of liquid to first occur before being passed into the drain tube.

Background of the invention and objects This invention pertains to liquid drains of a type primarily useful in draining liquid from a compartment which is to be maintained under a predetermined environmental state, as for example, as found in a refrigerated railroad car or semitrailer truck.

Special types of drain constructions for use in draining liquid from a refrigerated railroad car, for example, have been known and employed for many years. In providing a drain from a compartment which is to be maintained under a predetermined temperature state or other environmental condition, it is of considerable importance to limit the frequency with which the drain opening is in its opened condition. Obviously, the more frequently that the drain is open to the outside surroundings, the greater will be the escape of the environmental atmosphere within the compartment. However, where drains of the foregoing type are employed in refrigerated railroad cars or other vehicles which are subject to receiving frequent and varied road shocks and other vibrations, such drain valve constructions are subject to being frequently opened.

It is a general object of the present invention to provide an improved drain valve construction of a type suitable for use in vehicles or otherwise which serves to limit the frequency with which the valve is required to be opened.

It is another object of the present invention to provide a drain valve construction of the kind referred to above wherein a predetermined accumulation of liquid must first be acquired before the valve is opened.

In this manner, under certain circumstances it may never be necessary for the drain valves to open in view of the fact that liquid in lesser amounts may accumulate and then reevaporate into the controlled environment.

These and other objects of the invention will become more readily apparent when considered in conjunction with the following drawings, in which FIGURE 1 is a side elevation section view of a vehicle carrying a drain valve construction according to the invention;

FIGURE 2 is an enlarged elevation view in section and partially broken away showing the construction of FIG- URE l; and

3,460,561 Patented Aug. 12, 1969 g CE FIGURE 3 is a side elevation View of the drain tube assembly of FIGURE 2, shown removed from the vehicle.

Summary of the invention In general, there has been disclosed a drain valve construction comprising a drain tube carried to extend upwardly into a collection tray or other liquid collection means such as a portion of the floor of a vehicle. The upper end of the tube forms a sill to be crossed by liquid entering the upper end of the tube. The sill, therefore, defines a predetermined accumulation of liquid acquired by the collection tray. A closure member at the other end of the tube is operatively responsive to the weight of liquid within the tube so as to operate the closure member and thereby open the tube to discharge liquid therefrom.

In general, there is further provided means forming an enclosed liquid flow path running upwardly along the outside of the tube, across the sill, and into the tube in a manner forming a trap preventing entry of air into the compartment at pressures on the order of atmospheric.

Description of a preferred embodiment Referring to the drawings, a vehicle 11 such as a refrigerated railroad car includes a commodity compartment 12 of a type adapted to be refrigerated or heated so as to maintain a predetermined environmental state. In the floor 13 of compartment 12 there is formed a liquid collection tray or pan 14 preferably disposed at a low point in the floor 13. In this manner, liquids accumulating on the floor 13 would tend to drain into tray 14.

A drain tube 16 depends downwardly from beneath vehicle 11. The upper end of tube 16 extends upwardly into tray 14 to a point slightly below the brim 18 of tray 14. In this manner, the upwardly extending portion 19 forms a sill which serves to define the maximum accumulated liquid volume which can be acquired by tray 14. The upper end of tube 16 includes threads: 17 for attachment to a flanged collar 21 secured to the underside of tray 14 whereby the height of sill 19 can be variously adjusted. It is preferred, however, to position the upper lip 22 of sill 19 at a level slightly below floor level as defined by brim 18.

Means forming a liquid trap at the upper end of tube 16, as now to be described, serves to preclude the entry of air from the outside surroundings via tube 16.

Thus, an inverted cup member 23, formed along its lower edge with a plurality of rectangular fluid passages 24, serves to form an enclosed liquid flow path 26 running upwardly along the outside of tube 16 at its upper end and thence across lip 22 and into tube 16. In this manner, liquid accumulated in the collection tray 14 to the level 27 as defined by the upper edges of passages 24 serves to form a fluid trap to preclude the entry of atmospheric air into compartment 12.

At any time that liquid in tray 14 rises above lip 22, the liquid will spill over into the interior of tube 16 and with only the slightest accumulation of liquid within tube 16, the weight of the liquid will serve to move closure member 28 away from the valve seat 29 formed by the bottom edge of tube 16.

Tube 16 has been cut olf at its lower end at an angle on the order of 45 to the horizontal so as to form the valve seat 29 disposed in a plane extending upwardly for reasons and purposes now to be described.

By employing an upwardly inclined valve seat 29, means can be provided serving to normally urge closure member 28 to its closed position bearing against seat 29. Thus, a pair of lever arms 31, 32 are pivotally carried on pivot pins 33. The lower ends of arms 31, 32 are joined by closure member 28, whereas the upper ends of arms 31, 32 serve to carry cylindrical counter-weights 34. The center of gravity 36 of counter-weights 34 acts downwardly along line 37 to create a clockwise moment (as viewed in FIGURE 2) about pivot pin 33 which tends to close the bottom of tube 16. The weight of the structure carried below pivot pins 33 (including portions of lever arms 31, 32 and closure member 28) acts through the center of gravity 38 thereof to create an oppositely acting moment tending to open the lower end of tube 16.

Accordingly, closure member 28 is only slightly urged closed by the slightly greater moment created by counterweights 36 than by the weight of the structure acting through the center of gravity 38. Accordingly, upon accumulation of only the slightest amount of liquid within tube 16, closure member 28 will be moved aside so as to permit the liquid to escape.

Where vehicle 11 is subjected to road vibration and shock of a type, for example, as encountered when switching railroad cars, it will be readily apparent that vertically acting forces as might be caused, for example, by bouncing of the vehicle at such times, will have essentially no effect upon the closed condition of closure member 28 even though closure member 28 can be moved aside by only a slight accumulated volume of liquid within tube 16. Nor will horizontal forces have any significant effect upon closure member 28 due to the counteracting moments thus created.

This can be explained by the fact that the counterweights and closure member (including the mass of lever arms 31, 32 defined below pivot pin 33) have substantially comparable masses disposed to provide substantially equal counteracting moments of inertia in response to such vertical or horizontal bouncing movements of the vehicle and in this manner serve to essentially nullify any adverse effects which such movements might have upon closure member 28. Pivot pins 33 lie in a plane through the centerline of tube 16.

Even without water in tray 14 (and therefore in the absence of the air trap thus provided) closure member 28 tends to remain closed due to the differential in area within and without tube 16. When the compartment 12 is under refrigeration the pressure within compartment 12 can be expected to be less than the outside surroundings and this pressure differential will tend to maintain member 28 closed (in addition to the closing action provided by the slightly greater moment created by counterweights 36, as explained above).

In a refrigerator car there will generally be found bits and pieces of organic refuse subject to decay which will be discharged via tube 16. Accordingly, it is important that such pieces should not wedge their way into positions causing member 28 to remain open. The diagonal disposition of member 28 and valve seat 29 not only forms an extra large discharge mouth for tube 16, but serves to encourage such bits and pieces to move downwardly within tube 16 under the influence of the bouncing movement experienced by the refrigerator car. Thus, with a piece of refuse in tube 16, bouncing movement of the car will cause the piece to initially prop the closure member 28 slightly open. Each subsequent bouncing movement helps further prop open member 28. The

smooth bore of tube 16 permits the pieces to continue to work themselves downwardly until the wide mouth at the bottom of tube 16 passes the piece to the outside surroundings.

While tube 16 is held open by the above action, the

water trap formed in tray 14 precludes passage of air into or out of compartment 12.

From the foregoing, it will be readily apparent that by extending the upper end of tube 16 well into tray 14, the frequency of fluid discharge from tube 16 will be limited to only those occasions wherein sufiicient fluid has accumulated within tray 14 to overflow sill 19. In such circumstances, in addition, the foregoing construction provides an efiicient fluid trap serving to exclude from within compartment 12 air as might enter from the outside surroundings via tube 16 during discharge of fluid or refuse.

What is claimed is:

1. In a vehicle of a type having a cargo compartment adapted to be maintained at a given environmental state, the combination comprising collection means for accumulating liquid from within the compartment, a drain tube carried upwardly into said collection means, the upper end of said tube forming a sill to be crossed by liquid entering the upper end of said tube and defining a predetermined accumulation of liquid within said collection means, a closure member at the other end of said tube operable between closed and open conditions and operatively responsive to the weight of liquid within the tube to operate said closure member to said open condition to discharge liquid from the tube, characterized by pivotally supported lever arm means carrying said closure member, the pivot being disposed centrally above said closure member, the weight of said closure member creating a moment about said pivot tending to move said closure member to one of said conditions, a counterweight carried by said lever arm means and disposed to have a center of gravity above the pivot point to create an oppositely acting moment tending to move said closure member to the other of said conditions, one of said moments being slightly greater than the other to normally urge the closure member to its closed condition, said counter-weight and closure member having substantially comparable masses disposed to provide counteracting moments of inertia responsive both to vertical bouncing of thevehicle and sudden shock forces acting in each of two opposite horizontal directions so as to maintain said normally closed condition of said tube notwithstanding bouncing, or sudden acceleration or deceleration of the vehicle, thereby limiting the frequency of occurrence of said open condition.

References Cited UNITED STATES PATENTS 151,548 6/1874 Schmitz 137527.8 209,295 10/1878 Rogers 137396 1,004,913 10/1911 Salmini l37247.33 X 1,137,516 4/1915 Moon 137-247.33 X 1,168,085 1/1916 McKelvey 137396 1,184,554 5/1916 Miles 137-350 X 1,329,015 1/1920 Posson 137-247.33 1,707,330 4/1929 Stone 137-24735 X 2,110,927 3/1938 Zane 137247.37

FOREIGN PATENTS 240 1877 Great Britain.

WILLIAM F. ODEA, Primary Examiner D. H. LAMBERT, Assistant Examiner US. Cl. X.R. 137-396, 527 

